From GT New Horizons
GUI of an Advanced Extruder with a Rod extruder plate loaded. An OV Scanner is charging in the bottom center slot.
Charging in an Advanced Extruder

Many items in GT:NH require Electricity to work. Machines can be connected directly to power generators, but items must be charged in an appropriate GUI. Items will only charge in a machine that matches their desired power tier and type, which is usually the same tier of battery or circuit used to craft them if not listed. Virtually all single-block GregTech machines can charge EU by placing items in their power slot (center bottom, lightning bolt icon).

Battery Buffers can charge multiple items at once, not just batteries. For even faster charging, Battery Charger can be used which will provide up to 8A at once, power permitting.

Redstone Flux Charging

RF consumers such as the Electromagnet require a Redstone Flux charging option like a Capacitor Bank. They cannot be charged in GT devices with EU directly, but EU can be converted into RF by plugging a RF storage block (such as a Capacitor) into GT power. The reverse is not possible; RF cannot be converted into EU.

Armor Power
Advanced NanoChestPlate HV
Advanced Electric Jetpack HV
Draconic Armor RF
Electric Boots of the Traveller MV
Electric Jetpack (IC2) LV
GraviChestPlate EV
Nanosuit Armor HV
Nightvision Goggles LV
QuantumSuit IV
Wyvern Armor RF
SpaceSuit Jetpack[1] GC
Item Power
Cropnalyzer MV
Electromagnet RF
Energy Crystal HV
Industrial Grafter MV
Lapotron Crystal EV
Lapotronic Orb IV
OV Scanner MV
OD Scanner LV
Portable Scanner (Gregtech) MV
Scooporator MX200 Turbo MV
Staff of Travelling RF
  1. The SpaceSuit Jetpack needs a GalaxySpace or GalactiCraft EU storage block to charge in - Energy Storage Cluster, Energy Storage Module, Basic/Advanced/Hybrid Solar Panel.